P120 catenin is a regulator of cell-cell adhesion, achieved through interaction with classical and Type II cadherins. Evidence also exists for a role in the regulation of cadherin availability on the cell surface. P120 catenin also regulates actin dynamics, placing it as a potential master regulator of the cell motility/cell adhesion phenotypes.

Recent studies have suggested a tumour-suppression role for p120, with loss of p120 expression implicated in the development of a tumour microenvironment and induction of metastatic progression. The expression of p120 Catenin has been highlighted in early lobular breast neoplasias.